Semiconductor heterojunctions and superlattices are critical material structures for high performance electronic and opto- electronic devices. A broad program at Princeton is currently underway studying the basic physics, material growth processes, and device applications of these structures in three different material classes -- (1) III-V crystalline semiconductors, (2) silicon-based heterostructures, and (3) amorphous superlattices. For a complete research program in any of these material systems, it is necessary to know the composition of the grown films, the microstructure of the films and of the devices fabricated in them, and the transport properties of carriers in these films. Scanning electron microscopy (SEM) will be added to the laboratory to allow these meassurements. Energy dispersive x-ray analysis and beam induced current analysis will be required. The SEM will be a great aid to the research groups in all three of the above areas.
